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LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Rebollo De Miguel, M., et al. (2023). Measurement of the CKM angle γ using the B± → D*h± channels. J. High Energy Phys., 12(12), 013–32pp.
Abstract: A measurement of the CP-violating observables from B -> (DK +/-)-K-* and B-+/- -> D-*pi(+/-) decays is presented, where D-*(D) is an admixture of D-*0 and D-0 (D-0 and (0)) states and is reconstructed through the decay chains D-*-> D pi(0)/gamma and D -> KS0 pi+pi-/KS0K+K-. The measurement is performed by analysing the signal yield variation across the D decay phase space and is independent of any amplitude model. The data sample used was collected by the LHCb experiment in proton-proton collisions and corresponds to a total integrated luminosity of 9 fb(-1) at centre-of-mass energies of 7, 8 and 13 TeV. The CKM angle gamma is determined to be (69(-14)(+13))degrees using the measured CP-violating observables. The hadronic parameters r(B)(D)*(K +/-),r(B)(D)*(pi +/-),delta(D)(B)*(K +/-),delta(D)(B)*(pi +/-), which are the ratios and strong phase differences between favoured and suppressed B-+/- decays, are also reported.
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LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Rebollo De Miguel, M., et al. (2024). A model-independent measurement of the CKM angle γ in partially reconstructed B±→D∗h± decays with D→K0Sh+h-(h=π,K). J. High Energy Phys., 02(2), 118–30pp.
Abstract: A measurement of CP-violating observables in B-+/-->(DK +/-)-K-& lowast; and B-+/--> D-& lowast;pi(+/-) decays is made where the photon or neutral pion from the D-& lowast;-> D gamma or D-& lowast;-> D pi(0) decay is not reconstructed. The D meson is reconstructed in the self-conjugate decay modes, D -> K-S(0)pi(+)pi(-) or D ->(KSK+K-)-K-0. The distribution of signal yields in the D decay phase space is analysed in a model-independent way. The measurement uses a data sample collected in proton-proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of approximately 9 fb(-1). The B-+/-->(DK +/-)-K-& lowast; and B-+/--> D-& lowast;pi(+/-) CP-violating observables are interpreted in terms of hadronic parameters and the CKM angle gamma, resulting in a measurement of gamma=(92(-17)(+21))degrees. The total uncertainty includes the statistical and systematic uncertainties, and the uncertainty due to external strong-phase inputs.
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LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Rebollo De Miguel, M., et al. (2024). Search for CP violation in the phase space of D0 → KS0 K± π∓ decays with the energy test. J. High Energy Phys., 03(3), 107–20pp.
Abstract: A search for CP violation in D-0 -> (KSK+)-K-0 pi(-) and D-0 -> (KSK-)-K-0 pi(+) decays is reported. The search is performed using an unbinned model-independent method known as the energy test that probes local CP violation in the phase space of the decays. The data analysed correspond to an integrated luminosity of 5.4 fb(-1) collected in proton-proton collisions by the LHCb experiment at a centre-of-mass energy of root s = 13TeV, amounting to approximately 950 thousand and 620 thousand signal candidates for the D-0 -> (KSK-)-K-0 pi(+) and D-0 -> (KSK+)-K-0 pi(-) modes, respectively. The method is validated using D-0 -> K-pi(+)pi(-)pi(+) and D-0 -> K-S(0)pi(+)pi(-) decays, where CP-violating effects are expected to be negligible, and using background-enhanced regions of the signal decays. The results are consistent with CP symmetry in both the D-0 -> (KSK-)-K-0 pi(+) and the D-0 -> (KSK+)-K-0 pi(-) decays, with p-values for the hypothesis of no CP violation of 70% and 66%, respectively.
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